Flashcards in Chapter 21 - Environment and hominin culture Deck (13):
Define natural selection.
It is when individuals with less favourable genes are less likely to be passed on to the next generation and this leads to a species becoming better adapted to its environment.
Who are Anthropologists ?
People who study human societies and their development, may define culture as anything that is learned.
What are activities that are considered to be apart of culture?
-Making stone tools
-Using language and art
How can the cultural evolution be seen?
Through the gradual improvement in tools, better methods of obtaining food, increased sophistication of language and a host of other changes that have culminated in the highly complex culture that we have today.
The advantages of an erect stance, and the bipedal locomotion that evolved later, are:
1. An increased range of vision for detecting prey and predators at a greater distance.
2. Increased size, deterring predators.
3. Hands free for carrying food and, perhaps, for too use.
4. Higher reach when picking fruit from trees
5. Improved cooling of the body.
How does an erect stance, and the bipedal locomotion improved the cooling of the body?
1. When the body is vertical (instead of horizontal, as in quadrapedalism), the sum strikes a smaller fraction of it, helping to avoid overheating.
2. In addition, the upper body is above the ground where there is more wind to help cool the body and where air temperatures may be marginally lower than at ground level.
Define Home Bases
A camp site to which prehistoric hunters brought back food for sharing and with other members of their group.
What evidence have been found upon Home Bases?
-No evidence of the use of fire has been found to date, but tool use does appear to have been common.
-A range of pebble tools has been found, including choppers, scrapers, flakes and chisels.
-These vary from about the size of a tennis ball (choppers) to that of a marble (scrapers and flakes), and are frequently referred to as Oldowan tools, after the site where they were first discovered.
Interesting Fact about Migration.
1. Tool use by australopithecines enabled them to exploit a broader range of habitats, so they were eventually able to leave Africa and colonise other continents.
2. Evidence suggests that the australopithecines began to disperse from Africa around 2 million years ago.
3. They probably migrated north along the rift valley system, and then followed the Nile River into what is now Egypt, eventually going on to the Middle East and perhaps into Asia.
What caused migration among the Australopithecines?
This is unknown, but one possibility is that they were searching for more productive environments during the drier interglacial periods.
Give a detailed analysis of fossil evidence of Early Homo.
1. Homo walked upright and had hands that were more robust than those of modern humans.
2. They would have had a more powerful grasp than ours, similar to the grip of chimpanzees.
3. Like the modern apes, early Homo had a hand that would have been well suited to climbing trees.
-These 2 features suggest that early Homo may have walked bipedally during the day, with food-gathering expeditions into the tress.
-At night, it is likely that early Homo retired to the safety of the trees to sleep, much like some non-human primates today.
Why was the brain of early Homo significantly larger than that of the australopithecines?
1. The brain uses a lot of energy and can only grow larger in species that are routinely consuming high-energy food.
2. It's growth also needs complex fats that are hard to obtain or synthesise on a vegetarian diet.
3. For a brain to increase in size, a shift to meat eating would have been necessary.